Spin-dependent magnetoresistance and spin-charge separation in multiwall carbon nanotubes

The spin-dependent transport in multiwall carbon nanotubes obtained by chemical vapor deposition (CVD) in porous alumina membranes is studied. The zero bias anomaly is found to verify the predicted Luttinger liquid power law. The magnetoresistance at high fields varies in sign and amplitude from one sample to the other, which is probably due to the presence of dopant in the tube. In contrast, the magnetoresistance due to the spin polarized current is destroyed in the nanotube as expected in case of spin-charge separation.